Accumulated Other Comprehensive Income - Changes in AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Changes in AOCI by component
Beginning balance	$ 29,729	$ 55,896	$ 75,449
OCI before reclassifications	(2,702)	(27,481)	(10,866)
Amounts reclassified from AOCI	9,111	1,314	(8,687)
Net period OCI	6,409	(26,167)	(19,553)
Ending balance	36,138	29,729	55,896
Effective Portion of Cumulative Loss on Cash Flow Hedges
Changes in AOCI by component
Beginning balance	(65)	(97)	(604)
OCI before reclassifications	(284)	(709)	(865)
Amounts reclassified from AOCI	323	741	1,372
Net period OCI	39	32	507
Ending balance	(26)	(65)	(97)
Cumulative Unrealized Gain (Loss) on Available-for-Sale Securities
Changes in AOCI by component
Beginning balance	37,307	60,190	66,566
OCI before reclassifications	7,622	(17,487)	3,683
Amounts reclassified from AOCI		(5,396)	(10,059)
Net period OCI	7,622	(22,883)	(6,376)
Ending balance	44,929	37,307	60,190
Foreign Currency Translation
Changes in AOCI by component
Beginning balance	(7,513)	(4,197)	9,487
OCI before reclassifications	(10,040)	(9,285)	(13,684)
Amounts reclassified from AOCI	8,788	5,969
Net period OCI	(1,252)	(3,316)	(13,684)
Ending balance	$ (8,765)	$ (7,513)	$ (4,197)

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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